I can attest that WI sucks. Here, I'd suggest unloaded, in the box, with a lock, ammo elsewhere, maybe locked in the glovebox. If you get pulled over, God be with you...
This is cut and paste from:
http://www.gunlaws.com/links/linkswi.htm
All from 941.23 of
http://www.legis.state.wi.us/statutes/Stat0941.pdf
Excerpts and Points to Ponder...
To "go armed" does not require going anywhere. The elements for a violation of s. 941.23 are: 1) a dangerous weapon is on the defendant's person or within reach; 2) the defendant is aware of the weapon's presence; and 3) the weapon is hidden. State v. Keith, 175 Wis. 2d 75, 498 N.W.2d 865 (Ct. App. 1993).
A handgun on the seat of a car that was indiscernible from ordinary observation by a person outside, and within the immediate vicinity, of the vehicle was hidden from view for purposes of determining whether the gun was a concealed weapon under this section. State v. Walls, 190 Wis. 2d 65, 526 N.W.2d 765 (Ct. App. 1994).
This section is constitutional as applied in this case. The defendant's interest in exercising his right to keep and bear arms for purposes of security by carrying a concealed weapon in his vehicle does not substantially outweigh the state's interest in prohibiting him from carrying a concealed weapon in his vehicle. State v. Fisher, 2006 WI 44, 290 Wis. 2d 121, 714 N.W.2d 495, 04-2989.
A defendant was properly convicted under this section for driving a vehicle with a gun locked in a glove compartment. State v. Fry, 131 Wis. 2d 153, 388 N.W.2d 565 (1986).